Computation of Absorbed Power Densities in High-Resolution Head Models by Considering Skin Thickness in Quasi-Millimeter and Millimeter Wave Bands
Computation of Absorbed Power Densities in High-Resolution Head Models by Considering Skin Thickness in Quasi-Millimeter and Millimeter Wave Bands
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DOI：
10.1109/jerm.2022.3203576
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发表时间：
2022-12
影响因子：
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通讯作者：
K. Taguchi;Sachiko Kodera;A. Hirata;T. Kashiwa
中科院分区：
文献类型：
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作者：
K. Taguchi;Sachiko Kodera;A. Hirata;T. Kashiwa
第五代无线通信系统已被世界各地的通信公司越来越多地部署。该系统使用24ghz ~ 28ghz的高频频段。然而，评估人体对电磁场防护的研究数量在这个频段内是有限的。此外，两个主要的国际机构-国际非电离辐射防护委员会和ieee -分别在2020年和2019年修订了他们的指导方针和标准。一个主要的变化是在bbb6 GHz频率下的暴露度量和相应的暴露限制，因为在这些频率下，电磁波在生物组织中的穿透深度为1厘米或更小。因此，皮肤和皮下组织的建模是重要的。本研究评估了7种不同皮肤厚度的真人头部模型的总吸收功率（TAP）、吸收功率密度（APD）以及APD随皮肤厚度的变化。结果表明，未经表面平滑处理的模型比经过表面平滑处理的模型的TAP更高。由于强驻波的抑制作用，实际变化蒙皮厚度模型的TAP频域变化量小于均匀蒙皮厚度模型。APD的最大变化，平均超过4 cm2或1 cm2的皮肤厚度，分别约为20%和10%。对于入射功率密度的限制，apd低于指导值。这些结果将有助于今后修订国际准则。
The fifth-generation wireless communications system has been increasingly deployed by telecommunication companies worldwide. This system uses a high-frequency band ranging from 24 GHz to 28 GHz. However, the number of studies assessing the human protection from the electromagnetic fields is limited in this frequency band. In addition, two main international bodies—the International Commission on Non-Ionizing Radiation Protection and IEEE—have revised their guidelines and standard in 2020 and 2019, respectively. One primary change is the exposure metric and corresponding exposure limit at frequencies >6 GHz because the penetration depth of the electromagnetic waves in biological tissues is 1 cm or less for these frequencies. Therefore, modeling of the skin and subcutaneous tissues is important. This study evaluated the total absorbed power (TAP), the absorbed power density (APD), and variations in APD owing to skin thickness in seven types of realistic human head models with different skin thicknesses. Our results showed that the model without surface smoothing resulted in higher TAP than the model with smoothing. The amount of the TAP change in frequency domain in the model with realistically varied skin thickness was less than that in the model with uniform skin thickness because of the suppression of strong standing waves. The maximum variations in the APD, averaging over 4 cm2 or 1 cm2 with respect to skin thickness, were approximately 20% and 10%, respectively. For the limit of incident power density, APDs were below the guideline. These results will be useful for future revisions of international guidelines.